As part of our ongoing and global effort to build trust and encourage healthy conversation on Twitter, every part of the service matters. Follower counts are a visible feature, and we want everyone to have confidence that the numbers are meaningful and accurate.

Over the years, we’ve locked accounts when we detected sudden changes in account behavior. In these situations, we reach out to the owners of the accounts and unless they validate the account and reset their passwords, we keep them locked with no ability to log in. This week, we’ll be removing these locked accounts from follower counts across profiles globally. As a result, the number of followers displayed on many profiles may go down.

Most people will see a change of four followers or fewer; others with larger follower counts will experience a more significant drop. We understand this may be hard for some, but we believe accuracy and transparency make Twitter a more trusted service for public conversation.

Though the most significant changes are happening in the next few days, follower counts may continue to change more regularly as part of our ongoing work to proactively identify and challenge problematic accounts.

Why does an account get locked?

If we detect sudden changes in account behavior, we may lock the account and contact the owner to confirm they still have control of it. These sudden changes in account behavior could include Tweeting a large volume of unsolicited replies or mentions, Tweeting misleading links, or if a large number of accounts block the account after mentioning them. We sometimes lock an account if we see email and password combinations from other services posted online and believe that information could put the security of an account at risk — so we require accounts to change of their passwords for protection. Until we confirm that everything is ok with the account, we lock it, which makes them unable to Tweet or see ads.

How are these accounts different from spam or bots?

In most cases, these accounts were created by real people but we cannot confirm that the original person who opened the account still has control and access to it.

Spam accounts (sometimes referred to as bots) typically exhibit spammy behavior from the beginning, are increasingly predictable by our systems, and can be automatically shut down with our technology. You can learn more about our ongoing work to prevent spam on Twitter here.

Why just followers? Will this expand to Tweets, Likes, and Retweets?

Our ongoing work to improve the health of conversations on Twitter encompasses all aspects of our service. This specific update is focused on followers because it is one of the most visible features on our service and often associated with account credibility. Once an account is locked, it cannot Tweet, like or Retweet and it is not served ads.

No, it will not. Removing locked accounts from followers doesn't impact MAU or DAU. Locked accounts that have not reset their password in more than one month are not included in MAU or DAU. While today’s change doesn’t affect MAU or DAU, some accounts we remove from the service as part of our ongoing commitment to a healthy public conversation have the potential to impact publicly reported metrics.

Continuing to Communicate with You

This is another step to improve Twitter and ensure everyone can have confidence in their followers. Follow @Twitter and @TwitterSafety for the latest updates as we continue our commitment to serve the public conversation.